The present invention relates to a device for controlling fluid media, in particular a directional control valve, which includes at least one flow path that extends between at least two connections. The device includes a control unit equipped with an actuator that is coupled to at least one blocking element, which, in a blocking position, blocks the at least one flow path. Furthermore, the present invention relates to the use of a molded part in such a device, in particular in a directional control valve.
Devices of the aforementioned type, in particular, directional control valves, are known. For example, compact solenoid valves designed for use in the field of medical technology or analysis technology are known. Such valves are supposed to be suitable, in principle, for controlling aggressive or even highly aggressive media. This can include highly reactive media. Suitability for media requiring a high level of purity or, in general, sensitive media, is supposed to be given as well.
In this context, it is often preferable to provide a structural separation between flow paths, which are designed to conduct the media, and movable components of the valve, which can act on the flow paths, in order to selectively block or release a path for the media. One approach for this is to provide a so-called separation membrane, which is disposed between an actuator of the valve and at least one flow path and preferably forms at least one part of a line section. Such a separation membrane can therefore bring about, at least in sections, a hermetic (material) separation between the flowing media and the actuator.
It has been shown, however, that deposits, corrosion or even component damage, which is traced back to the media used, can also occur in valves provided with separation membranes in the manner described above. This can increase the amount of cleaning and maintenance and even repair, if necessary, that is required. Conversely, a contamination of the media can also pose a threat, and so a considerable amount of effort is required for cleaning, disinfection, or even sterilization.
Furthermore, it has been shown that in the case of compact valves, in particular, which is referred to basically as so-called microvalves, the required cleaning, maintenance and/or repair work is difficult due to poor accessibility. The tendency toward increasingly more compact valves in the medical field, in the laboratory field, and in the field of analysis would further increase these disadvantages.
Valves, which are also suitable for aggressive or even highly aggressive media, often require the use of high-quality materials at least in the flow-guiding parts thereof. The high-quality materials are stainless steel or special plastics, for example, which have an at least adequate resistance to media.